Carrier route record
WNPHX→GEG
Southwest Airlines · Phoenix to Spokane
- Flights
- 618
- Period
- September 2025 to August 2026
- Share of route
- 49%
- Carriers
- 4
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on PHX to GEG sits in the middle of the pack with a C+. Close to three flights in four arrive on time by the DOT's definition, 3 points worse than the national rate of 77.3%. The late ones land about 40 minutes behind schedule. That rests on 618 flights, with a median arrival 1 minute late.
The US average over the same twelve months is 77.3%, so there is little to separate Southwest on PHX to GEG from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
73.9%
Arrivals under 15 minutes late, of 613 completed flights
Avg delay
39 min
Across delayed arrivals only, not all flights
Cancelled
0.65%
National rate is 1.89%
Whole route
73.9%
Every carrier on PHX to GEG, 1,264 flights
These figures cover 618 flights between September 2025 and August 2026. On-time means an arrival less than 15 minutes after the scheduled gate time, the same threshold the Department of Transportation uses in its own reports. Cancelled and diverted flights are excluded from the on-time rate and counted separately, which is why the cancellation column matters on its own.
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Carrier by carrier
Southwest against every carrier on PHX to GEG
Southwest flew 618 of the 1,264 flights on PHX to GEG, about 49% of it. Its 73.9% on time is about level with the route as a whole at 73.9%. Ranked by on-time rate it is number two of four carriers on the route, where the range runs from American at 74.4% to Frontier at 68.9%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| American Airlines | 591 | 74.4% | 71 min | 0.34% | C+ |
| Southwest Airlines (this page) | 618 | 73.9% | 39 min | 0.65% | C+ |
| Envoy Airthin sample | 10 | 70.0% | 47 min | 0.00% | C+ |
| Frontier Airlinesthin sample | 45 | 68.9% | 79 min | 0.00% | C+ |
Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
Departure window
When Southwest runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 31 points, against half a point between the best and worst carrier.
- 5am–8am14 flights—
- 8am–11am211 flights87.1%
- 11am–2pm140 flights76.4%
- 2pm–5pm77 flights72.4%
- 5pm–8pm13 flights—
- 8pm–5am163 flights55.6%
Scale runs 45% to 95%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 55.6% on time, against 87.1% for the 8am–11am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 8am–11am window is the busiest, with 211 flights scheduled in it.
Across the year
Southwest on PHX to GEG through the year
June is the worst month at 52.8% on time, 41 points below January, the best at 93.3%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. March was the busiest month here, with 62 flights.
Across the week, Saturday is the strongest day at 78.4% on time and Wednesday the weakest at 66.2%, a spread of 12 points.
Arrival by arrival
How late Southwest on PHX to GEG runs when it is late
Most of the lateness is short. 85 of the 160 late arrivals were under half an hour behind, and 28 reached an hour or more.
- 15+ min early83 flights13.5%
- Within 15 min370 flights60.4%
- 15–29 min late85 flights13.9%
- 30–59 min late47 flights7.7%
- 1–2 hours late24 flights3.9%
- 2+ hours late4 flights0.7%
Scale runs 0% to 100%.
Share of 613 completed flights by arrival against schedule.
57 of 194 late departures made up the time and arrived on time, 29% of them. 23 flights left on time and still arrived late.
The worst days
Worst days for Southwest on PHX to GEG
The latest arrival of the period was on 26 December 2025, 3 hours 6 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. Three of the five worst days fell in July 2026.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 26 December 2025 | 3 hours 6 minutes | Late-arriving aircraft |
| 2 July 2026 | 2 hours 6 minutes | Carrier |
| 22 July 2026 | 2 hours 3 minutes | Carrier |
| 19 September 2025 | 2 hours | Late-arriving aircraft |
| 13 July 2026 | 1 hour 54 minutes | Late-arriving aircraft |
Delay causes
Why Southwest runs late on this route
Late-arriving aircraft accounts for 49% of the 6,311 delay minutes carriers reported here, and the remaining four split what is left.
- 49%Late-arriving aircraft
- 39%Carrier
- 11%National Airspace System
- 1%Extreme weather
49% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 6,311 reported delay minutes here, that single category outweighs weather by 39 to one. The split is drawn from 6,311 reported delay minutes.
The largest share of delay minutes, 39%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 2,438 of the 6,311 delay minutes reported here.
Cancellations are rare at 0.65%, below the national 1.89% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.
Connections and stage length
What a delay here costs
Badly late arrivals are rare here: only 4.6% land an hour or more behind schedule, against 8.3% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.
The 1,020 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty.
The return leg is a different operation and performs like one: it runs 84.8% on time across 618 flights, 11 points above this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 11 points of difference.
One caution: this is a thin sample. 618 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
What to do with this
Booking Southwest on PHX to GEG
Put together: treat all of this as provisional. 618 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 73.9% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 613 completed flights over 12 months sit behind that.
Related
Where to go next
- PHX to GEG, every carrier
- Southwest on GEG to PHX, the return leg
- American Airlines on PHX to GEG74.4%
- Southwest Airlines network-wide record
- Phoenix Sky Harbor International (PHX) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.05 million flight records
Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.